Let's make this an excercise in dogfooding: let's turn on more security
features for all our long-running services.
Specifically:
- Turn on RestrictRealtime=yes for all of them
- Turn on ProtectKernelTunables=yes and ProtectControlGroups=yes for most of
them
- Turn on RestrictAddressFamilies= for all of them, but different sets of
address families for each
Also, always order settings in the unit files, that the various sandboxing
features are close together.
Add a couple of missing, older settings for a numbre of unit files.
Note that this change turns off AF_INET/AF_INET6 from udevd, thus effectively
turning of networking from udev rule commands. Since this might break stuff
(that is already broken I'd argue) this is documented in NEWS.
Mere presence of the socket in the filesystem makes
udev_queue_get_udev_is_active() return that udev is running. Note that,
udev on exit doesn't unlink control socket nor does systemd. Thus socket
stays around even when both daemon and socket are stopped. This causes
problems for cryptsetup because when it detects running udev it launches
synchronous operations that *really* require udev. This in turn may
cause blocking and subsequent timeout in systemd-cryptsetup on reboot
while machine is in a state that udev and its control socket units are
stopped, e.g. emergency mode.
Fixes#2477
This was causing preset-all --global to create symlinks:
$ systemctl preset-all --global --root=/var/tmp/inst1
Created symlink /var/tmp/inst1/etc/systemd/user/shutdown.target → /usr/lib/systemd/user/../system/shutdown.target.
Created symlink /var/tmp/inst1/etc/systemd/user/sockets.target → /usr/lib/systemd/user/../system/sockets.target.
Created symlink /var/tmp/inst1/etc/systemd/user/timers.target → /usr/lib/systemd/user/../system/timers.target.
Created symlink /var/tmp/inst1/etc/systemd/user/paths.target → /usr/lib/systemd/user/../system/paths.target.
Created symlink /var/tmp/inst1/etc/systemd/user/bluetooth.target → /usr/lib/systemd/user/../system/bluetooth.target.
Created symlink /var/tmp/inst1/etc/systemd/user/printer.target → /usr/lib/systemd/user/../system/printer.target.
Created symlink /var/tmp/inst1/etc/systemd/user/sound.target → /usr/lib/systemd/user/../system/sound.target.
Created symlink /var/tmp/inst1/etc/systemd/user/smartcard.target → /usr/lib/systemd/user/../system/smartcard.target.
Created symlink /var/tmp/inst1/etc/systemd/user/busnames.target → /usr/lib/systemd/user/../system/busnames.target.
It is better to create units in a state that completely matches the presets, i.e.
preset-all should do nothing when invoked immediately after installation.
I'm sure it was confusing to users too, suggesting that system and user units
may somehow alias each other.
This complements graphical-session.target for services which set up the
environment (e. g. dbus-update-activation-environment) and need to run before
the actual graphical session.
Udev rules cover all the necessary initializations.
As the service now is neither installed, nor installable - we can
remove explicit dependencies and RemainAfterExit=yes option.
This unit acts as a dynamic "alias" target for any concrete graphical user
session like gnome-session.target; these should declare
"BindsTo=graphical-session.target" so that both targets stop and start at the
same time.
This allows services that run in a particular graphical user session (e. g.
gnome-settings-daemon.service) to declare "PartOf=graphical-session.target"
without having to know or get updated for all/new session types. This will
ensure that stopping the graphical session will stop all services which are
associated to it.
If user isolates rescue target from multi-user or graphical target (or just
starts the service), IgnoreOnIsolate will cause issues with sulogin which is
directly started on current virtual console. This patch adds necessary
Conflicts= and Before= against rescue.service.
Note that this is not needed for emergency target, as implicit Requires= and
After= against sysinit.target is in effect for this service
(DefaultDependencies=yes).
https://github.com/systemd/systemd/pull/3685 introduced
/run/systemd/inaccessible/{chr,blk} to map inacessible devices,
this patch allows systemd running inside a nspawn container to create
/run/systemd/inaccessible/{chr,blk}.
When a container scope is allocated via machined it gets 16K set already since
cf7d1a30e4. Make sure when a container is run as
system service it gets the same values.
udevd already limits its number of workers/children: the max number is actually
twice the number of CPUs the system is using.
(The limit can also be raised with udev.children-max= kernel command line
option BTW).
On some servers, this limit can easily exceed the maximum number of tasks that
systemd put on all services, which is 512 by default.
Since udevd has already its limitation logic, simply disable the static
limitation done by TasksMax.
Specifically "machinectl shell" (or its OpenShell() bus call) is implemented by
entering the file system namespace of the container and opening a TTY there.
In order to enter the file system namespace, chroot() is required, which is
filtered by SystemCallFilter='s @mount group. Hence, let's make this work again
and drop @mount from the filter list.
Quoting @cgwalters:
Just uploading this as an RFC. Now I know reading the code that systemd says
`Welcome to $OS` as a generic thing, but my initial impression on seeing this
was that it was almost sarcastic =)
Let's say "You are in emergency mode" as a more neutral/less excited phrase.
This patch is based on #3556, but makes the same change for rescue mode.
In order to improve compatibility with local clients that speak DNS directly
(and do not use NSS or our bus API) listen locally on 127.0.0.53:53 and process
any queries made that way.
Note that resolved does not implement a full DNS server on this port, but
simply enough to allow normal, local clients to resolve RRs through resolved.
Specifically it does not implement queries without the RD bit set (these are
requests where recursive lookups are explicitly disabled), and neither queries
with DNSSEC DO set in combination with DNSSEC CD (i.e. DNSSEC lookups with
validation turned off). It also refuses zone transfers and obsolete RR types.
All lookups done this way will be rejected with a clean error code, so that the
client side can repeat the query with a reduced feature set.
The code will set the DNSSEC AD flag however, depending on whether the data
resolved has been validated (or comes from a local, trusted source).
Lookups made via this mechanisms are propagated to LLMNR and mDNS as necessary,
but this is only partially useful as DNS packets cannot carry IP scope data
(i.e. the ifindex), and hence link-local addresses returned cannot be used
properly (and given that LLMNR/mDNS are mostly about link-local communication
this is quite a limitation). Also, given that DNS tends to use IDNA for
non-ASCII names, while LLMNR/mDNS uses UTF-8 lookups cannot be mapped 1:1.
In general this should improve compatibility with clients bypassing NSS but
it is highly recommended for clients to instead use NSS or our native bus API.
This patch also beefs up the DnsStream logic, as it reuses the code for local
TCP listening. DnsStream now provides proper reference counting for its
objects.
In order to avoid feedback loops resolved will no silently ignore 127.0.0.53
specified as DNS server when reading configuration.
resolved listens on 127.0.0.53:53 instead of 127.0.0.1:53 in order to leave
the latter free for local, external DNS servers or forwarders.
This also changes the "etc.conf" tmpfiles snippet to create a symlink from
/etc/resolv.conf to /usr/lib/systemd/resolv.conf by default, thus making this
stub the default mode of operation if /etc is not populated.
Add a line
SystemCallFilter=~@clock @module @mount @obsolete @raw-io ptrace
for daemons shipped by systemd. As an exception, systemd-timesyncd
needs @clock system calls and systemd-localed is not privileged.
ptrace(2) is blocked to prevent seccomp escapes.
In the same vein as commit ac59f0c12c which added
the --wait option to the emergency service, this patch makes sure that plymouth
has exited before entering into the rescue mode.
In order to support stateless systems that support offline /usr updates
properly, let's restore the ConditionNeesUpdate=/etc line that makes sure we
are run when /usr is updated and this update needs to be propagated to the
/etc/ld.so.conf file stored in /etc.
This reverts part of #2859, which snuck this change in, but really shouldn't
have.
Add a synchronization point so that custom initramfs units can run
after the root device becomes available, before it is fsck'd and
mounted.
This is useful for custom initramfs units that may modify the
root disk partition table, where the root device is not known in
advance (it's dynamically selected by the generators).
When enabling ForwardToSyslog=yes, the syslog.socket is active when entering
emergency mode. Any log message then triggers the start of rsyslog.service (or
other implementation) along with its dependencies such as local-fs.target and
sysinit.target. As these might fail themselves (e. g. faulty /etc/fstab), this
breaks the emergency mode.
This causes syslog.socket to fail with "Failed to queue service startup job:
Transition is destructive".
Add Conflicts=syslog.socket to emergency.service to make sure the socket is
stopped when emergency.service is started.
Fixes#266
Container images from Debian or suchlike contain device nodes in /dev. Let's
make sure we can clone them properly, hence pass CAP_MKNOD to machined.
Fixes: #2867#465
That way we can be sure that local users are logged out before the network is
shut down when the system goes down, so that SSH session should be ending
cleanly before the system goes down.
Fixes: #2390
With the current "Type=forking", systemd tries to guess the PID it
should wait on at reboot (because we have no "PIDFile="). Depending on
how wrong the guess is, we can end up hanging forever at reboot.
Asking it not to do that eliminates the problem.
Also drop ConditionNeedsUpdate=|/etc. Regardless if system is updated
online or offline, updating dynamic loader cache should always be
responsibility of packaging tools/scripts.
When using `%I` for instances of `systemd-nspawn@.service`, the result
will be `systemd-nspawn` trying to launch a container named e.g.
`fedora/23` instead of `fedora-23`.
Using `%i` instead prevents escaping `-` in a container name and uses
the unmodified container name from the machine store.
This commit rips out systemd-bootchart. It will be given a new home, outside
of the systemd repository. The code itself isn't actually specific to
systemd and can be used without systemd even, so let's put it somewhere
else.
As kdbus won't land in the anticipated way, the bus-proxy is not needed in
its current form. It can be resurrected at any time thanks to the history,
but for now, let's remove it from the sources. If we'll have a similar tool
in the future, it will look quite differently anyway.
Note that stdio-bridge is still available. It was restored from a version
prior to f252ff17, and refactored to make use of the current APIs.
This reworks the coredumping logic so that the coredump handler invoked from the kernel only collects runtime data
about the crashed process, and then submits it for processing to a socket-activate coredump service, which extracts a
stacktrace and writes the coredump to disk.
This has a number of benefits: the disk IO and stack trace generation may take a substantial amount of resources, and
hence should better be managed by PID 1, so that resource management applies. This patch uses RuntimeMaxSec=, Nice=, OOMScoreAdjust=
and various sandboxing settings to ensure that the coredump handler doesn't take away unbounded resources from normally
priorized processes.
This logic is also nice since this makes sure the coredump processing and storage is delayed correctly until
/var/systemd/coredump is mounted and writable.
Fixes: #2286
Now that requiring of a masked unit results in failure again, downgrade the dependency on /tmp to Wants= again, so that
our suggested way to disable /tmp-on-tmpfs by masking doesn't result in a failing boot.
References: #2315
Yu Watanabe